Draft gear



Sept. 18, 1928.

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Sept. 18, 1928. 1,684,388

' w. H. COTTON DRAFT GEAR Filed March 23, 1925 4 Sheets-Sheet 2 [22 7/872 Jon.- 7/62 2& 2 (566042 Sept. 18, 1928. 1,684,388

w. H. COTTON DRAFT GEAR Filed March 23, 1925 4 Sheets-Sheet 3 Patented Sept. 18, 1928.

series.

WALTER H. COTTON, OF CHICAGO, ILLINOI AEELGIJQR TO UEQ'IOH DRAFT GEAR CODI- PANY, OF CHICAGO, ILLINOIS, A CSRPC-RATKOIQ' OF DELAW'ARE.

DRA-FT GEAR.

.Applicationfiled March 23, 1925.

This invention relates to shock absorbing devices and more particularly to draft, gears for railway cars.

One of they objects of the invention. is the provision of new and im rovednneans for positively relieving the pressnrepn the friction elements at each end of the gear inclepcndentl v of each other.

Another object of the invention is the provision of new and imp ovedmeans for creating pressure on the friction elements and for returning the parts to normal position after compression.

A further object of the invention is the provision of new and improved frictionelements that may he easil; ass nhied and idily placed in position n the. f; .lowcr hous ngs.

A still further object of the inveni'ionis the provision of new and improved draft that is sinipie in constriuition, cheap to manu i'acture, easily assemhied. composed of relativch, small. number of parts, is efiicient in operation and that is not, likely to become broken or get out of order.

Other and further objects and advantages of the inventimi will appear from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a horizontal section of a draft gear showing the same in operative position, with parts broken away;

Fig. 2 is a section on line 2--2 of Fig. 1;

Fig. 3 is a perspective view of one of the shoes or Wedges;

Fig. l is a perspective View ofone of the friction plates;

Fig. 5 is a vertical section of one of the friction blocks or shells;

Fig. 6 is an end elevation of one of the follower members or sleeves;

Fig. 7 is a view similar to Fig. l hut showing a modified form of the device;

Fig. 8 is a perspective view of one of the friction plates employed in the form of the device shown in Fig. 7;

Fig.- 9 is a perspective view of one of the friction blocks or shells'en'iployed in connectionwith the device shown in Figs. 7, l1 and 12;

Fig. 10 is a similar vie of one of the wedges or friction shoes employed in connection with the devices shown in Figs. 7, 11 and 12;

Fig. 11 is aiew similar to Fig. 1 showing Serial ,No. ,17,612.

a further modified form of the device in compressed position;

Fig. 12 is a similar view showing the gear expanded Fig..l3 is a section on linel3 l3 of Fig. 12; and

Fig. M is an elevation of one of the chambered followers employed in the form of the device shown in Figs. 11 and 1 On the drawings the reference character it) designates the usual ccnter sills of a rail way car which are provided with the forward or draft lu' ll andwith the rear or buffer lugs '12, as is usual in such constructions.

Referring now more particularly to the form of the device shown in Figs. 1 to 6 inchisive, the dra t gear denoted generally by th reference character 13 adapted to he insertcd between the two sets of lugs ll and 12. of the draft bar or head The yoke l1 if) is adapted to encircle the drsft gear 13 in the usual manner.

The gea r i3 is composed of a follower member at each end thereof. iflach followergnemher comprises a followerhar or block 16 and a casing followeror sleeve 17. The blocks 16 are interposed between the sleeves l7 and the correspon ding lugs ll and 12 on the center sills 10. The sleeves 17 are in the form of open ended casings which are provided at their outer, ends with inwardly extendinglugs 18 and 19, see Fig. 6, diagonally arranged or arranged in staggered relation for forming anchors or abutnicnts. for the springs aswill presently appear.

A group of intercalatedfriction plates are arranged at each side of the longitudinal axis of the gear,-each group comprises the two sets of friction plates 21 and overlapping at their inner ends as cl aarly shownin 1 of the drawings.

lnterposed between the two groups of friction plates are the friction members or shells Q0 and 23. Suitable means are provided for forcing the plates laterally into frictional engagement with said friction members or shells. V In the formof the device selected to illustrate an emhocinicnt of the invention. the follower casings are enlarged laterally at their inner endsthat is. the inner portions of the side walls of the follower casings are offsetas at 24 to form recesses 25 and inclined shoulders 26. Friction shoes or wedges 27 provided with inclined shoulders 28 for engaging the shoulders 26 on the sleeves are mounted in said recesses and are provided with flat surfaces for frictionally engaging the friction plates at each side of the casing.

Suitable means are provided for resiliently resisting the inward movementof the shoes or wedges during compression of tie gear whereby the camming or wedging action of the cooperating inclined shoulders or wedging surfaces 26 and 28 will force the friction plates 21 and int-o frictional contact with each other, thereby absorbing the shocks incident to the operation of the cars on which the device is installed. It is desirable that resilient means he also employed to return the parts to normal position. In the present invention the resilient means employed for resisting the inward movement of the shoes or wedges are also employed for releasing the wedges and for returning the parts to normal position after compression. This is considered an important feature of the invention because it insures a positive release of the wedges at each end of the gear immediately after compression thereof.

In the form of the device disclosed in Figs. 1 to 6, each of the central friction members or shells 23 is provided with a plurality of openings 29 and 31 preferably arranged in pairs. The openings 29 extend entirely through the shell while the openings 31 are closed at their outer ends as indicated at in Figs. 1 and 5. As shown, the shells are provided with two pairs of openings, the members of each pair being diagonally arranged from each other, whereby the springs will exert a balanced pressure on the shells as will presently appear.

A plurality of resilient members, as the coil springs 83 and 34 are adapted to engage in the openings 29 and 31 in the friction members or shells 20 and 23. These springs are arranged in pairs to correspond with the openings in the shells 20 and 23. As shown in Fig. 1, the left ends of the springs 33 extend entirely through the shell 20 and engage the lugs 18 of the sleeve 17 while their ends at the right of said figure engage the bottom walls 32 of the openings 31 in the shell 23. On the other hand, the left ends of the springs 34 engage the bottom walls of the openings in the shell 20 while the right ends extend through the shell 23 and engage the lugs 19 on the corresponding sleeve. By means of this arrangement each follower 17 is forced outwardly by a pair of springs that are diagonally arranged relative thereto and that are anchored in the central friction member at the opposite end of the gear, thereby insuring a positive releasing action of each follower with its wedging means.

Suitable means are employed for returning the friction shoes and plates to normal position after compression. This is preferably accomplished by locking the shoes and plates to the central friction members or shells 20 and 23. One manner of accomplishing this is shown in Fig. 1. The shells 20 and 23 and friction shoes 27 are provided at opposite sides with alined recesses 35 and 36, respectively, in which are mounted retracting bars 37. The friction plates are all alike and each has its inner end reduced to form shoulders 38 which are adapted to be engaged by the retracting bars 3'? when the same are moved outwardly after COHIPLGSSlOIl, but will not interfere with the inward movement of said bars during compression.

The friction plates are so arranged that their outer ends will not contact the follower blocks 16 in the expanded position of the gear. Upon compression of the gear, the follower blocks 16 will cause the inward movement of the sleeves or casing followers 1?, and since the inward movement of the shoes will be resisted by the springs through the shells and retracting bars, transverse pressure will be placed 'on the plates before the outer ends of the same are engaged by the follower blocks. When the outer ends of the plates are engaged by the follower blocks, the plates will be forced inward and by their frictional resistance upon each other will absorb the shock. Upon release of the compressive force, the springs will promptly force the sleeves outwardly, thus relieving the transverse pressure on the friction plates, whereby the springs will immediately return the parts to normal position of the expanded gear.

In assembling the device, the friction plates, shoes, springs and retracting bars are assembled and the sleeves placed on the ends thereof, after which the device, as a single unit, may be placed in position between the follower blocks 16.

In the operation of the device, assuming the parts to be in the position shown in Fig. 1, a force applied to the yoke 14 in either direction will tend to move the blocks 16 inwardly against the sleeves, which in turn. through the engagement of their inclined shoulders with the shoes will tend to move the same inwardly, but the resistance of the springs to the inward movement of the shoes will cause the same to move laterally, thereby creating lateral pressure on the friction plates. On further compression of the gear the follower blocks will come into engagement with the ends of the two sets of friction plates and cause a relative movement between the same. The frictional resistance to the relative movement of the platrw will cushion the movement of the yoke or absorb the shock causing said movement.

In the form of the device shown in Figs. 7, 8. 9 and 10 a single retracting bar for each shell and set of plates is employed. The general arrangement of the parts is substantially the same as that shown in Figs. 1 to 6 described above, differing from that construction in details 'Which Will'noW be pointed out.

In this form of the device'each side of the sleeve 59 inwardly of the inclined shoulders 42 is cut away at 43 thereby permitting the interior of the sleeve to be slightly wider thanis possible in the form shown in Figs. 1 to 6, thus affording additional space for the friction elements. The frirtion blocks or shells -'tt5,'see Fig. 9, differ from that previously described in that the openings provided in the upper and lowersurfaces'of the shells for the reception of the springs fi'a'n'd 48, respectively, are in the form of grooves 44 and 45. The groovessl are closed at their outer ends, as at 480 to'form seats for the outer ends of the corresponding springs as shown inFig. 9. The shells may be coredas atto lighten the same. and cachis provided with a transverse 'opening through which a retracting bar 54 is adapted to extend.

A group of friction plates is arranged at each side of the friction shell as in the previous construction. Each plate 45) provided with'an opening 51 at one end for engag ing one of the'retracting barand with a slot 52 at the otherend for receiving the other retracting bar. The 'openingfii elongated in order to permit aslight movement of the retracting bar relatively to the plate. as usual in such"constructions. The inner end of each plate is slotted for accomnuidat'ing the relative movement of the plate'and oppo site retracting bar during the operation of the gear, as is well understood in the art.

The wedging members or shoes 56 are each provided with a plane surface 57 for engaging the friction plates 49. and on the opposite side, with an inclined shoulder or wedging surface 58 for engaging the corresponding inclined shoulder or wedging surface -12 on the sleeve 59. Each shoe is provided with an aperture tit) for receiving one end of the retracting bar A boss 61 may be provided about the aperture for engaging the re tracting bar for assisting in holding said shoe in operative position, and for forming a long bearing for slidably el'igaging the retracting bar. The shoes move with the bars during the operation of the gear.

in the compression of the gear, the elongated openings 51 in the friction plates will permit a limited movement of the bars 54 relative to the friction plates whereby the wedging shoes will be forced laterally against. the friction plates before the followers engage the ends of the friction plates. as in the previous construction.

The form of the device shown in Fi s. ll, 12. 13 and ll differs from that shown in igs. 'i' to 10. inclusi 'e, in that follower member 32 is constructed as a unitary structure. In this form of the device. the follower blocks (31) are integral with the walls of the plate receiving portion of the follower member and may if desired be cored as at (El in order to lighten the same. The follower members are cut away as at (35' and are provided with inclined shoulders or wed' ing surface (36 for engaying thewedges a as in the former construction. The shells to. spring: ll, and a -l and the retracting bars 5-! and their arrangement are substantially the same a in the mnstruetion disclosed in Figs. T to l l. im-lusive. ('lescribed above.

It is thought from the foregoing talrenin connection with the'acconipanying drawiugs. that the ctmstwation and operation of my device will be apparent to thosesltilled in the art. and that various change; in sire. s: proportion and details of con truction to; i made without departing from the spirit-and scope o t the appended claims.

I claim as my invention:

1. A draft gear comprising a pair of follower casings. intercalat'ct t. .ction element 1 within said casings. means for creating lat-- eral 'wressure on said elements during co epression of said gear. and separate mean for releasing said pressure at each end of said gear after compression, said means comprising a plurality of sp ings within said CIIs'iLV-"A extending substantially the length of said gear.

2. In C(Yllil'tlllfll'ltlfl, a pair of fo'llowercasings, friction elements within said casings. means for creating lateral pressure onsaid elements during; compression of said -gear. central members for frictionally engaging said friction elements, and resilient members each having one end engaging one of said casing and its other end in engagement with one of said central members.

33. In combination. a pair of follower casings, friction members Within said casings. intercalated friction plates at each side of said members. means at each end of said gear for forcing said plates into frictional engagement with said friction members. and means for independently and simultaneously releasing the pressure at each end of said gear after compression.

4. A draft gear comprising, a central friction member, a group of intercalated friction plates at; each side of said member. means movable longitudinally of said gear for causing lateral pressure on. and relative movement of. said plates during compression, and means including resilient men'ibers between said groups of plates tending to si multaneously relieve the lateral pressure on said plates and to return the parts to normal position after compression.

5. A draft gear comprising a pair of casing followers, a pair of friction blocks within said casings, a group of friction plates at each side of said blocks, means for forcing said plates inwardly against said blocks during compression of said gear, and a plurality of springs each having one end engaging one of said blocks and its other end in engagement with one of said followers.

6. A friction n'ieniber for draft gears comprising a shell having a friction surface at each side thereof, said shell being provided with two sets of openings, one set of said openings extending entirely through said shell and the other set having their outer ends closed, and the members of each set being arranged diagonally from each other relatively to said shell.

7. In combination, a pair of follower sleeves having dia onally arranged tabs extending inwardly from the outer ends thereof, a pair of friction shells within said sleeves, relatively movable friction elements within said sleeves, said elements being in frictional engagement with each other, means for creating lateral pressure on said elements and shells during compression of said gear for increasing the friction between said elements, and coil springs each having one end anchored on one of said shells and its other end extending through the other shell and engaging one of said tabs.

8. A draft gear comprising a pair of followers, a pair of friction shells, a groap cf intercalated friction plates at each side of said shells, means for forcing said platesinto frictional engagement with said shells, and means for returning the parts to normal position after compression, said means comprising a pair of springs engaging one of said shells and one of said followers, and diagonally arranged relative to said shell, and a pair of springs between the other follower and shell and diagonally arranged relatively to said last named shell.

9. A draft gear comprising a pair of follower members, friction shells within said members, a group of intercalated friction plates at each side of said shells, means for forcing said plates against said shells during compression of said gear, and means for returning the parts to normal position after compression, said means comprising springs each having one end only engaging one of said followers and a retracting bar at each end of said gear.

10. In a draft gear, a pair of follower members, friction elements within said menr bers, means for creating lateral pressure on said elements during compression of the gear, and two sets of springs one set engaging one of said elements and one of said followers and the other set engaging another of said elements, and another of said follovers.

ll. A draft gear comprisinga pair of opposed follower members, friction means within said follower members for resisting the compression of said gear, springs holding said means in frictional engagement, each spring engaging a follower at one end of the gear and the friction means at the other end of the gear, part of the springs engaging one follower and part the other follower.

In testimony whereof I aflix my signature.

WALTER II. COTTON. 

